The hybrid direct current (DC) breaker has good static characteristics and good dynamic characteristics. The multi-terminal high-voltage direct current (HVDC) transmission network is largely dependent on the development of DC circuit breaker technology. This paper presents a hybrid DC circuit breaker based on arc voltage

and derives mathematical relationship of current-commutation. Simulating the key part-high speed switch by the electro-magnetic repulsion mechanism is performed using finite element analysis. A 1 kA/15 kV hybrid DC breaker is designed based on the above research

and the test results show that the prototype’s arc maximum current-commutation capacity is 3 kA. The process of current transfer from high-speed switch to solid state switch accords with the exponential function

and is consistent with theoretical derivation. The prototype can break the short-circuit current less than 10 kA within 5 ms

and the break time depends primarily on high-speed switch and arc voltage.